摘要
The electronic structure and electrochemical parameters of ternary NiSn0.5Ti0.5 phase are investigated by plane-wave pseudopotential method of the first-principle.The interstitial sites are firstly filled with lithium atoms,and then the substitution for Ni sites occurs.The results show that the Fermi level of lithium-intercalated phase goes up with the increasing lithium concentration.These interactions of M-M covalent bonds (M=Ni,Sn,Ti) become weak,while Li-M bonds are found to increase.NiSn 0.5Ti0.5 phase is characterized with high theoretical capacity and low voltage of lithium-intercalation.The obvious volume effect from 77.15%to 189.94% would lead to the failure of the electrode material,and therefore the NiSn0.5Ti0.5 compound should be limited as low as possible in multi-element Sn-based alloy.
The electronic structure and electrochemical parameters of ternary NiSn0.5Ti0.5 phase are investigated by plane-wave pseudopoten- tial method of the first-principle. The interstitial sites are firstly filled with lithium atoms, and then the substitution for Ni sites occurs. The results show that the Fermi level of lithium-intercalated phase goes up with the increasing lithium concentration. These interactions of M-M covalent bonds （M=Ni, Sn, Ti） become weak, while Li-M bonds are found to increase. NiSn0.5Ti0.5 phase is characterized with high theoretical capacity and low voltage of lithium-intercalation. The obvious volume effect from 77.15% to 189.94% would lead to the failure of the electrode material, and therefore the NiSn0.5Ti0.5 compound should be limited as low as possible in multi-element Sn-based alloy.
基金
supported by the National Natural Science Foundation of China(50771046)
